<template>
  <el-select ref="diyselect" class="noselect" v-model="valueTitle" :clearable="clearable" @clear="clearHandle">
    <el-option class="noselect" :value="valueTitle" :label="valueTitle">
      <el-tree  id="tree-option"
        ref="selectTree"
        :accordion="accordion"
        :data="options"
        :props="props"
        :default-checked-keys="[value]"
        :node-key="props.value"
        :default-expanded-keys="defaultExpandedKey"
        @node-click="handleNodeClick">
      </el-tree>
    </el-option>
  </el-select>
</template>

<script>
export default {
  name: "el-tree-select",
  props:{
    /* 配置项 */
    props:{
      type: Object,
      default:()=>{
        return {
          value: 'id',             // ID字段名
          label: 'menuName',         // 显示名称
          children: 'children',    // 子级字段名
          valuetype: 'menuName'
        }
      }
    },
    /* 选项列表数据(树形结构的对象数组) */
    options:{
      type: Array,
      default: ()=>{ return [] }
    },
    /* 初始值 */
    value:{
      type: String,
      default: ()=>{ return '' }
    },
    /* 可清空选项 */
    clearable:{
      type:Boolean,
      default:()=>{ return true }
    },
    /* 自动收起 */
    accordion:{
      type:Boolean,
      default:()=>{ return false }
    },
  },
  data() {
    return {
      valueId: this.value,    // 初始值
      valueTitle:'',
      defaultExpandedKey:[]
    }
  },
  mounted(){
    console.log(this.value)
    this.initHandle()
  },
  methods: {
    // 初始化值
    initHandle(){
      if(this.valueId){
        // this.valueTitle = this.options.find(item => item.id == this.valueId)[this.props.valuetype]
        // this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[this.props.label]     // 初始化显示
        this.$refs.selectTree.setCurrentKey(this.valueId)       // 设置默认选中
        this.defaultExpandedKey = [this.valueId]      // 设置默认展开
      }
      this.$nextTick(()=>{
        let scrollWrap = document.querySelectorAll('.el-scrollbar .el-select-dropdown__wrap')[0]
        let scrollBar = document.querySelectorAll('.el-scrollbar .el-scrollbar__bar')
        scrollWrap.style.cssText = 'margin: 0px; max-height: none; overflow: hidden;'
        scrollBar.forEach(ele => ele.style.width = 0)
      })

    },
    // 切换选项
    handleNodeClick(node){
      console.log(node)
      this.valueTitle = node[this.props.label]
      this.valueId = node[this.props.value]
      this.$emit('getValue', this.valueId)
      this.defaultExpandedKey = []
      this.$refs.diyselect.blur()
      // if (!node.children.length) {
      //   this.$refs.diyselect.blur()
      // }
    },
    // 清除选中
    clearHandle(){
      console.log('test')
      this.valueTitle = ''
      this.valueId = null
      this.defaultExpandedKey = []
      this.clearSelected()
      this.$emit('getValue', '')
    },
    /* 清空选中样式 */
    clearSelected(){
      let allNode = document.querySelectorAll('#tree-option .el-tree-node')
      allNode.forEach((element)=>element.classList.remove('is-current'))
    },
    findMenu: function (item, pId) {
      var menuindex = item.findIndex(item => item.id == pId)
      if (menuindex >= 0) {
        this.valueTitle = item[menuindex][this.props.valuetype]
        return
      } else {
        var flag = false
        for (let i = 0; i < item.length; i++) {
          if (item[i].children.length != 0) {
            this.findMenu(item[i].children, pId)
            flag = true
          }
        }
        if (!flag) {
          return
        }
        
      }
    }
  },
  watch: {
    value(){
      if (!this.value || this.value == '00000000-0000-0000-0000-000000000000') {
        console.log('kong')
        this.$refs.selectTree.setCheckedKeys([])
        this.valueTitle = ''
      } else {
        console.log('you')
        this.valueId = this.value
        this.findMenu(this.options, this.valueId)
        // this.valueTitle = this.findMenu(this.options, this.valueId)
        // this.valueTitle = this.options.find(item => item.id == this.valueId)[this.props.valuetype]
        // debugger
        // this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[this.props.label]
        this.initHandle()
      }
    }
  },
};
</script>

<style scoped>
  .el-scrollbar .el-scrollbar__view .el-select-dropdown__item{
    height: auto;
    max-height: 274px;
    padding: 0;
    overflow: hidden;
    overflow-y: auto;
  }
  .el-select-dropdown__item.selected{
    font-weight: normal;
  }
  ul li >>>.el-tree .el-tree-node__content{
    height:auto;
    padding: 0 20px;
  }
  .el-tree-node__label{
    font-weight: normal;
  }
  .el-tree >>>.is-current .el-tree-node__label{
    color: #409EFF;
    font-weight: 700;
  }
  .el-tree >>>.is-current .el-tree-node__children .el-tree-node__label{
    color:#606266;
    font-weight: normal;
  }
  .noselect {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
  }
</style>
